Studies will be on human renal carcinoma (RC) transitional cell tumors (TCT) of the genitourinary tract. To support these investigations a tumor and serum bank has been established. TCT's and RC's and control tissues have been grown in long term culture. Cell lines have been established from both primary and metastatic tumors. These cell lines will be utilized as follows: 1. Virological Studies - TCT. An RNA virus has been isolated from TCT in tissue culture and from surgical specimens. A long term cell line produces virus-like particles. These particles contain RNA and have reverse transcriptase enzyme. Fluids of TCT also produce malignant in vitro transformation in mammalian cells. Future studies will (a) characterize TCT-associated virus and (b) study further the transformation phenomenon and the immunology of the transformed cells. 2. Immunological Studies. TCT and RC assays to measure in vitro serum and lymphocyte mediated cytotoxicity (LMC) have been developed. Studies to examine enhancement or blocking of LMC will be continued. Attempts will be made to correlate patient immunological response with clinical course. 3. Biochemical Studies - RC. Studies on lipid metabolism in normal and neo-plastic renal cells will be continued. Specifically cholesterol transport, synthesis and metabolism will be studied. These studies will employ techniques of tissue culture, classical virology, molecular virology, immunology, biochemistry and electron microscopy.